Field of the Invention
Embodiments of the present disclosure relate to a drill insert, more particularly embodiments relate to an indexible drill insert for use in a pocket of a drill body. Embodiments of the present disclosure also relate to a rotary cutting tool employing such an insert.
Background Information
Drilling tools are used to form cylindrical holes in workpieces formed from metals and other hard materials. The cutting or boring action of the drilling tools may be carried out by an elongated, substantially cylindrical drilling tool, such as a combination of a tool holder and a drill insert, which is selectively attached thereto. Such an arrangement may then be used in an application wherein one end of the tool holder is securely mounted in a driving apparatus, such as a chuck mechanism of a machine tool, which rotates the tool holder about its longitudinal axis. At the opposite end of the elongated tool holder, the cutting insert engages the workpiece material to be machined. Alternatively, the workpiece may be made to rotate relative to the holder and cutting insert, such as in positioning the holder in the tail stock of a lathe or the like. Further, the tool holder and workpiece may both be made to rotate relative to one another. The use of replaceable cutting inserts allows for quick changing of the insert upon wear of the cutting surfaces instead of the entire tool, and allows for one tool to be used for a variety of different boring applications by simply changing the insert and not the entire drill assembly.
The indexible drill inserts plays an important role in drilling because typically multiple sides of an insert can be used for cutting one after the other. Further, use of inserts generally reduces manufacturing lead time and assembling time.
The use of quadra angular indexible drill inserts is known in the art, however, the inserts which are in the art comprise four rectangular cutting edges for cutting the workpiece. The use of rectangular cutting edges tends to make the drill drift away from its center because the cutting forces act generally all over the drill body and not exactly at the center. The drill drift further creates a narrow wall which is not feasible in practical applications. Further, conventional indexible drill inserts rub the surface of the drilling hole if the diameter of the drill hole is less than the predetermined value.
In the view of above mentioned disadvantages, it is necessary to develop an improved drill insert having four identical cutting edges.